Method and apparatus for treating waste containing organic contaminants

Abstract

A system including a method and apparatus for treating waste containing organic contaminants which includes a direct fired, countercurrent, rotary kiln providing a soaking zone having an oxidizing atmosphere through which the materials being treated are passed after the unwanted organics are removed, and a secondary combustion chamber for oxidizing gases containing vaporized or pyrolyzed organics in which the organics are burned and are subjected to high temperatures for a holding time sufficient to effect destruction of the organic contaminants. The system includes means to minimize off-gas so as to make possible a reduction in size of the equipment employed.

What is claimed is: 
     
       1. A vertically oriented combustion unit for oxidizing large volumes of gaseous and vaporized organic materials, including walls defining an upper burner section, an intermediate holding section and a lower cooling section, said sections being interconnected and in free communication with one another, each of said sections being generally circular at horizontal cross section, said burner section including means defining an upper primary combustion zone having a generally cylindrical peripheral wall and a generally bulbous secondary combustion zone defined by upper walls which slope outwardly and downwardly from the cylindrical wall of said primary combustion zone, a generally cylindrical intermediate wall connected with said upper wall and a lower wall which slopes inwardly from said cylindrical wall to a central opening, an inlet for the gaseous material to be burned, passageway means connecting said gaseous inlet to a plurality of openings in the cylindrical wall of said primary combustion zone and a plurality of openings in said upper wall of said secondary combustion zone, a burner in the upper end of said primary combustion zone, means supplying said burner with a hydrocarbon fuel, means for supplying combustion air into said primary combustion zone adjacent said burner and for supplying combustion air into said primary combustion zone and around said openings for the gaseous material into said primary combustion zone and around the openings for the gaseous material in the upper wall of said secondary combustion zone, the opening in the upper wall of said secondary combustion zone being oriented to provide rotative flow in said combustion zone whereby turbulent mixing of the gases and combustion air occurs in said primary and secondary combustion zones to assure uniform temperatures therein, a holding zone communicating with said lower opening of said secondary combustion zone, said holding zone being defined by generally cylindrical wall means and being proportioned to have a volume sufficient to hold gases emanating from said combustion zones for a predetermined period of time, said holding zone communication with a cooling zone form which said gases are discharged. 
     
     
       2. The unit of claim 1 wherein injectors for liquid materials containing hazardous organics extend into said primary secondary combustion zones to permit the simultaneous oxidation of the hazardous organics in both liquids and gases. 
     
     
       3. The unit of claim 2 wherein a plurality of liquid material injectors are provided in said secondary zone at a plurality of spaced apart locations around the periphery of said secondary zone. 
     
     
       4. The unit of claim 3 wherein said injectors in said secondary zone are oriented to inject liquid radially into said secondary zone. 
     
     
       5. The unit of claims 1, 2, 3, or 4 wherein a plurality of water injections are provided in said secondary zone at a plurality of spaced apart locations around the periphery of said secondary zone whereby control of the temperature in said zone may be effected through the injection of water into said secondary zone.